1. Field of the Invention
The invention relates to a hand-held rotary tool that reduces vibration caused in a tool body when a tool bit is rotationally driven.
2. Description of the Related Art
Japanese non-examined laid-open Patent Publication No. 1987-74564 discloses a vibration-proofing device for a hand-held power tool in the form of a disc grinder. In the above-mentioned known vibration-proofing device, a gear housing which houses a mechanism for driving a tool bit in the form of a grinding wheel, and a motor housing which houses a motor for driving the grinding wheel and has a grip to be held by a user are connected to each other by an elastic element. When the grinding wheel is driven and vibration is caused in the gear housing, the elastic element serves to reduce transmission of this vibration to the grip via the motor housing.
The above-described known vibration-proofing device is designed such that the motor housing is allowed to move in all directions relative to the gear housing by the elastic element. Therefore, during operation, the grip and the gear housing (the grinding wheel) are irregularly displaced in all directions relative to each other, so that usability decreases. In this point, further improvement is desired.